Function: 1. Compact design can be put into BCD pocket, it can also be hung. 2. PU coated nylon fabric, abrasion resistant PU outer shell, can effectively protect the inner side. 3. Erasable interior pages and pencils are interchangeable. 4. PP composite material inside, front and back with hard pad, easy to write. 5. There are 2 clear inner bags on the back for different data tables. 6. 4 pencil storage bags can hold 4 spare pencils at the same time. 7. There is a strong D at the bottom that can be hung on the BCD hook. 8. The outer plate is equipped with an elastic band with a hook for fixing the inner side. Specification: Item Type: Underwater Notebook Material: PU coated nylon fabric waterproof PP synthetic paper Color: as shown in the picture Close size: approx. 20x12,5x1,5cm / 7,9x4,9x0,6 inch Internal page size: approx. 17,5 x 10,5 cm / 6,9 x 4,1 inch Inner side: 25 Weight: approx. 0,27 kg List of packages: 1 x Underwater Notebook Please be aware: